Dead Man's Frequency

Marco Leyva heard the signal at 3:22 AM on a Tuesday, which was not unusual — he spent most of his Tuesdays scanning the shortwave bands from his apartment in Cartagena, listening to the ocean of radio noise that covered the planet like an invisible sea. What was unusual was the frequency. 7.345 megahertz had been assigned to Estacion Aguila, a military communications relay in the Sierra Nevada that had been decommissioned in 2006. The station had been stripped, the equipment removed, the building sealed. Nothing should have been broadcasting on that frequency. Nothing had been broadcasting on that frequency for twenty years. Until now.

The signal was weak but clean — too clean for a pirate station, which would have shown the ragged edges of improvised equipment. This was a professional broadcast, properly modulated, with the distinctive tonal signature of military-grade transmitters. Marco adjusted his antenna and let the signal resolve, and what came through his speakers was a voice he recognized. Not from personal acquaintance but from the files — the case files he had been compiling for three years, ever since he had started investigating the disappearance of the Estacion Aguila staff. Six technicians had been stationed at the relay when it was decommissioned. All six had vanished. The official report said they had been reassigned. The reassignment records did not exist.
The voice belonged to Sergeant Esteban Rivas, the station's chief communications officer. It was calm, measured, professional — the voice of a man reading coordinates from a logbook, which was exactly what he was doing. A string of numbers, repeated twice, followed by a word that Marco did not recognize, followed by a countdown. The countdown started at seventy-two hours. Marco wrote down everything, replayed the recording four times, and then sat in his apartment in the pre-dawn darkness and tried to understand how a dead man could be broadcasting from a dead station on a frequency that no longer existed.